Mast structure



Oct- 9, 1951 H. J. wooLsLAYER ETAL 2,570,901

MAST STRUCTURE 2 Sheets-Sheet 2 Filed 001'.. 9, 1946 Patented Oct. V9, 1951 2,570,901- MAST` STRUCTURE Homer J.Woolslayer, Erwin A; Campbell, and Cecil Jenkins, Tulsa., Okla., assignors, by mesne assignments, to Lee C. Moore Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Application October 9, 1946, Serial No. 702,156

This invention relates to oil well derricks or mast structures which are adapted to be assembled in sections on the ground and then swung upwardly into upright position. The mast structure disclosed herein is an improvement on the one disclosed in our Patent No. 2,271,578.

It is among the Yobjects of this invention to provide a mast structure in which either short or tall masts may be raised and lowered equally well, in which a mast can be swung into upright position safely, which can be converted quickly for handling either short or ltall masts, and which can have Ymaximum thickness consistent with highway Vtransportation restrictions.

In accordance with this invention the foot of a mast is hinged to a base so that it can be swung upwardly from prone position to upright position after it has been assembled along the ground, and also can be swung back down again so that it can be moved to a new location. A line extends downwardly in the upright mast from its upper end and is connected to the usual drum for pulling the line up in the mast or lowering it therein. Mounted on the base beside the mast is a gin pole that is used in raising and lowering the mast.

The mast itself is variable in height. When it is short or of moderate height it can be swung up into operative position by means of a sling formed from a cable doubled upon itself. The ends of the cable are connected to the head of the gin pole while the opposite end of the sling is connected to the line inside the mast. When this line is pulled toward the head of th mast the sling raises the mast. The sling passes under sheaves mounted in the mast, preferably at aboutv the level of the top of the gin pole when the mast is erect. If the height of the mast is increased, a longer sling is used in place ofthe one just mentioned. This sling is connected .to the outside of the mast at points above the head of the gin pole when the mast is upright, and extends down around sheaves connected to the head of the pole and up into the mast where itis connected to the line mentioned-before. These sheaves preferably are carried by members which are rotatably mounted on a horif zontal axis in the head of the gin pole. The lower ends of the mast legs on the side adjacent the gin pole preferably terminate above the head of the pole by which they are supported'when the mast is standing up. l

The invention is illustrated in the accompanying ldrawings in which Fig. 1 is a -view Aof the gin pole side of the lower Yportion of 'the mast;

2 Claims. (Cl. 254-139) Fig. 2 is a side view of the structure; Fig. Sis

tional detail of the upper end of the gin pole andY the adjoining portion of a tall mast; Fig. 5 is a View similar to the preceding ligure but showing how the gin pole is used with a short mast', Fig. 6 is a diagrammatic View of this mast struc-- ture, with a tall mast about to be swung upv into upright position from the ground; Fig. 7-

is a fragmentary side View of the upper end of a gin pole provided with diierent means for connecting slings to it; and Fig. 8 is an enlarged front View of one of the sheave supporting members shown in Fig. 4.

Referring to the drawings, the foot of a vertical oil well derrick or mast I is mounted on a supporting base 2 so formed as to be sldable along the ground or transportable from one location to another as desired. The mast is made from preiabricated sections that have been as-l sembled at the well site to form a mast extending along the ground, as shown in Fig. 6. It has a pair of legs 3, which only for convenience of description shall be called front legs, hinged to the base by means of brackets d and removable pivot pins 6, as shown in Fig. 2. The lower ends of the opposite or rear legs 1 of the mast are located a considerable distance above the base and are connected to the lower ends of the front legs by inclined braces 8.

The mast is swung up into erect position with the aid of a tapered gin pole that also supports the mast when it is upright. The gin pole is formed from legs, for convenience here called front and rear legs 9 and II, respectively, which converge upwardly as shown in Fig. 2 and are hinged together at the top of the pole at points I2 so that the rear legs can be folded against the front legs when the mast is down. The lower ends of the front legs may be pivotally connected to pivot pins B in brackets 4, while the lower ends of the rear legs of the gin pole are detachably connected by means lof pins I5l to shoes I3 mounted in the base behind the mast.

The inclined braces 8 at the bottom of the mast rest against the front of the tapered gin pole which thereby supports the mast in upright position. The mast is detachably connected to the gin pole by eye bolts I4 pivotally supported by plates I6 secured to the lower ends of the rear legs of the mast. The lower ends of these mounted on the upper ends of the rear Y' legs of the gin' pole. The upper ends of the front legs of the gin pole are connected by a heavy tubular member I8 on the center of which a pulley I9 (Fig. 1) is rotatably mounted. A drilling line 2l extends upwardly from a. drawworks drum 22 past this pulley to the crown block 23 (Fig. 6)

and then down inside the mastv where Vthe line.

supports, the,usual traveling blocky 24 (Fig. 6) provided with a hook 25. During erection of the mast the drilling line passes over pulley i9 as shown in Fig. 6.

Rotatably mounted on each endof tubular.A

member I8 is a bracket 2t ormedas, shown inV Figs. 4 and 5, by a U-shapeplateLinwhich.is..

. The U -shape i platehas parallel. o

welded a short tube 2l that is r-otatablymourlld on member i8. ends projecting from the tubes, anda center piece 28 is welded between thoseprog ectingV When a mast that is short or of moderate ends. height is to be raised to operative position, a

relatively short sling 29; is .attachedjo` these,4 brackets and tothe h-ookof thetraveling block..

inside thedrneast. This sling is formed from a cable doubled upon-itselfvwith its endsV detachf ably. conneoted. to theouter` ends of center piece 28 aseshownin Fig. 5. Thelsling, indicated in partloy a brokenlifneoinV Fig. 6, passes under a.

pairrofvsheaves 3sv journaled in the mast near its rrear legs and at about. the. level vottheir lowerA ends. 'The sling; is looped over traveling block hookk 25 inside the mastl When the drawworks drumeisdrivenuto reelin the drilling line, the

traveling block moves toward the header, crownblockoflthe mast and simultaneouslypullsV on the sling to shorten theldirstance between the head of the mast and the headl of lthe gin pole. This combined actionrof line.v and sling` raises the mast until it is erectA Therlocation of sheaves 363 at the lower ends ointhepreanlegs` of the mast places them but a :x

short distance above the head of the gin pole when the mast is erect, as shown injFig. 2. Consequently, as the rising 'mast approaches itsseat on the gin pole the sling extends substantially horizontally from thepole to sheaves .fill This produces a gradual and substantiallyv` uniform.

pull on `the mast-so that it Vapproaches-thegin pole 4slowly instead of4 being'vrnore, or lesssnapped against the pole as isv thecasefwhen sheaves 3l) tubular member Syopposite-'to center ,piece 28,/

and plates 32 support a pin flonfwhicha-sheave 3l is journaled. In place of sling 29, alongor double sling38 is u sed.l This Yslinglikewisey is formed from a cable doubled Iupon Y, itself, but i its free ends are connected toYA lugs 3S...on.the rear legs of the mast. aYVconsider-able.- distance from their lower ends., The sling V extends from these lugs to thelgin pole where it passesaroundthe sheaves 3l,l and then extendseinto thema-stand around sheaves 30. The free end of the sling is looped over hook 2570i the travelingblocks This double slingY is shown in-full linesin Fig. 6 in. readiness .for raisins the; mast- Vilbel@- the be allowed to swing down into the gin pole until it is desired to lower the mast. They likewise canl be removed from the brackets if theI heightpfthe mast isreduced so that the multiple pulleyadvant'age ofdithe double sling line no longer visneeded,

In .Eig.7.: a.dii`1erent way of connecting the slingstoothetop of the gin pole is shown. Thus, a sheave llll is rotatably mounted in the upper end. oigeach side of the gin pole and is provided with a pair of transverse openings to which a bracket-42 -maybe `dei-,achably connected. by. re-

movable pins Theoutenerd of each'bracket..

is pivotally connectedbya pin ld/to a`terin-in`al.v member A 45 securedtoan end of cable sling., by which shortmasts are raised and loweredlas previously described. When a tall mast isV to,l beraised, pins 43 are removed inforder1 'to` disconnect brackets42 from sheavesiswhich then.v are free to rotate. The long; sling.v38, shownfin, broken lines, then canbepassed around -the two, sheaves.

It will benoted in Fig. 2 that the point,.l2 at',I which the front and rearlegs of the gin 'polearel hinged together is substantially directly belowI the lower ends'oftherear legsl of the mast and isas closeas thosev lowerendsto thefront legs, 3` of the mast. It also will be seen that the head; of the gin pole doesl not projectan appreciable. amount behind avertical plane parallel to, tl'ie"t I front of the mast and passing through theLmo'sti rearward point of the mast, which is 'at the rear.k edges. of plates I6 at theheel of the mast. In this arrangement, with the head of the gin pol'e1 beneath the` heel of the mast, the combined,

. thickness of mast and gin pole from front toback through the head of the gin pole when it isiolded; against theinast is substantially no'greater than the thickest part of the mast, which is abovesthe: ginv` pole.. Thereason for this arrangement .is to: permit the`- mast tobe thicker at the heel than, otherwise would be allowed. That is, in trans-. porting-thesemasts in sections on trucks over highways, the lower sections generally arelaid. onjtheirl sides with thev gin. poles folded againstl them, itbeing the practice to leavethe ginlilol'es' attached toA themasts.. As there are higl'iway restrictions which limit the width of truck loads, usually to. eight feet,l if the head of the gin polefv is located behindthe rearlegs of the mast the thickest partof the mast must be enough less than eight feet through to allow for thethickness. of the gin polehead. In other words, the com-,- bined`maximum thickness of mast and folded gin pole must, not exceed the highwaylimitation. By. locatingy the head of the gin pole beneath'the' heel of themast. in themannerdisclosed inthe drawings* the mast rrcan. be-.approximately eight feet thick at the heelbecause the foldedginlpole doesrgnot add to the thickness ofjthev mastand therefore does Y(nothaiveto be taken into account;

According to the,provisionsof-the patent stat- Y utes, we have explainedthe principle and confl struction of our invention and:y have illustrated and described whatwe nowcon,sid,er toY repre; Sr1t,. its best @mln@lillnsntq However. .Wesdesic 5 to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

We claim:

1. A mast structure intended for use with both short and tall masts that are designed to be swung up into upright position from prone position with the help of cable slings extending into the masts, said structure comprising a base, means on the base adapted to hinge the foot of a mast thereto, a gin pole mounted on the base behind said hinging means, a pair of laterally spaced brackets pivotally mounted on a horizontal axis at the head of the gin pole and having projecting ends adapted to be connected to the opposite ends of a cable which has been doubled upon itself to form a sling for swinging a short mast upward, supportingr means connected to each bracket and having an end projecting therefrom, and sheaves journaled in the projecting ends of said supporting means so that a sling can extend from inside a tall mast and around the sheaves to anchor points on the back side of that mast when it is desired to raise a tall mast instead of a short one.

2. A mast structure intended for use with both short and tall masts that are designed to be swung up into upright position from prone position with the help of cable slings extending into the masts, said structure comprising a base,

means on the base adapted to hinge the foot of a mast thereto, a gin pole mounted on the base behind said hinging means, a pair of laterally spaced brackets pivotally mounted on a horizontal axis at the head of the gin pole and having projecting ends formed for connection to the opposite ends of a cable which has been doubled upon itself to form a sling for swinging a short mast upward, supporting means detachably connected' to each bracket and having an end projecting therefrom in the direction opposite to said projecting end of the bracket, and sheaves journaled in the projecting ends of said supporting means so that a sling can extend from inside a tall mast and around the sheaves to anchor points on the back side of that mast when it is desired to raise a tall mast instead of a short one.

HOMER J. WOOLSLAYER. ERWIN A. CAMPBELL.

CECIL JENKINS.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,271,578Y Woolslayer et al. Feb. 3, 1942 2,363,106 Woolslayer et al. Nov. 21, 1944 2,403,081 Hilborn July 2, 1946 

